Electroosmotic fractionation of glue and gelatin



Patented 3.11. 9, 1934 UNITED sTATEs ELECTBOOSMOTIC FRACTIONA TION OF GLUE AND GELATIN Alexander Jenny, Berlin, Germany,

Siemens Elektro-Dsmose, G. m.

assignor to b. 11., Siemensstadt, near Berlin, Germany, a corporation of Germany Application October 2, 1929, Serial No. 396,660, and in Germany November 16, 1928 2 Claims. (Cl. 204-1) My invention relates to improvements in the production of gluten-like substances, and more particularly to the electro-osmotic iractionation of glue and gelatin. 4

It is well known in the art that gelatin may be fractionated by introducing the solution of gelatin to be treated into the anodic central compartment of a so-called tour-cell apparatus and filling the three remaining compartments of this apparatus with water. Such an apparatus contains at both sides the two electrode compartments the diaphragms of which are impermeable to gelatin and a central chamber which by a diaphragm permeable to gelatin is subdivided into a cathodic and an anodic central compartment. In this known process a portion of the gelatin diffuses under the influence of a direct electric current through the diaphragm located in the central chamber from the anodic central compartment into the cathodic compartment and is here dissolved in the water contained in this compartment. Two gelatin fractions are thus obtained which have diiierent properties.

According to my invention the same object may be attained in a diil'erent manner, viz, by introducing the solution to be treated into the cathodic central compartment of a four-cell osmotic apparatus. If the remaining three cells are filled with water a portion of the gelatin migrates into the anodic central compartment under the influence of a direct electric current. This anodic migration as well as the well known cathodic migration may be carried so far that the gelatin solutions in the two central compartments attain the same concentration. It will be understood, however, that the process may be interrupted prior to the equalization in the concentration being attained.

The known as well as my improved process so far as described above have the-drawback that the concentration of the final liquor is throughout considerably lower than that of the initial liquor.

If, for instance, the two central compartments have the same capacity and the process is carried on until equalization of the concentration is attained, solutions are produced which have only hall the gelatin content of the initial solution.

In order to eliminate this drawback tbesame gelatin liquor may according to a further development oi my invention from the beginning be filled into the two central compartments separated by a diaphragm permeable to gelatin and only the two electrode compartments may be charged with water. Under the assumption that the two diaphragms separating the outer electrode compartments from the central compartments adjoining towards the middle of the apparatus are impermeable to gelatin, a separationof the gelatin liquor into two fractions is in this case obtained-without dilution and without any losses. A portion of the gelatin liquor -central compartment into the anodic and another portion migrates at the 'same time from the anodic into the cathodic central compartment. The two fractions possess, as tests have proved, at any moment of the electro-osmotic treatment the same concentration and may be subjected to further treatment in the customary manner without difilculty. Both fractions dirfer very substantially in their properties. While the liquor contained in the anodic central com partment shows an acid reaction comparatively quickly after the switching on of the electric current the liquor of the cathodic central compartment soon gives an alkaline reaction.

' This separation into an acid and an alkaline fraction cannot solely be ascribed to the presence of organic ions, since the two reactions continue to exist even after the last content of ashes has been removed from the liquor.

My improved process'may, if desired, be continued up to the complete removal 01 the ashcontent. The duration of my improved process depends mainly on the use to be made oi the two fractions.

Ii, for example, the fraction produced in the cathodic central compartment is to be used for the manufacture of emulsion gelatin for photographic plates, the process is interrupted after complete or partial removal of the ash-content while the reaction is still. alkaline. If required a change of the properties of the final liquor may migrates'during this process from the cathodic be attained by making the two central compartments of difierent or of equal size.

The last described modification of my improved process is particularly suitable to turn gelatins useless for phctograrhic purposes into excellent emulsion gelatins. According to my improved process even very inferior gelatin-containing substances may be worked into very useful gelatins. My process may even be applied to gluten containing raw materials saturated with water or suspended in water, and subjected to well known preliminary treatments, such -as bones, leather, skin and the like. The initial liquors may be mixed with additional substances prior to or during the electro-osmotic treatment lit i erence throughout all the figures of the draw- Referring to the drawing a is a receptacle or vat in which are suspended two plate electrodes 2 and c, the electrode 7) being'connected as anode and the electrode as cathode. At the inner face of the electrode in there is located a diaphragm (land at the inner side of the electrode c the diaphragm e. The compartment containing the anode b and confined by the anodic diaphragm d is designated as the anode compartment while the compartment containing the cathode c and confined by the cathodic dia- --.,phragm e is called the cathode compartment.

The central chamber located between the two diaphragms d and e is again subdivided by a diaphragm f, into an anodic central compartment adjacent to the anode b and a cathodic central compartment adjacent to the cathode c. The diaphragm is usually described as the migration diaphra.

rowers The four-cell osmotic apparatus illustrated in the drawing for carrying out my improved process is worked in the manner described hereinbefore.

I claim as my invention:

1. The process of electro-osmotic fractionation of solutions of the glue or gelatin in a four-well electro-osmotic apparatus, which consists in interposing, between the electrodes of said apparatus and the said solution, diaphragms impermeable to gelatin, dividing said solution into two bodies by a diaphragm permeable to gelatin, and passing an electric current through the solution in such a manner as to cause portions of the gelatin to migrate from one of said bodies anodically to the other and from the last mentioned body cathodically to the one first mentioned.

2. The process of electro-osmotic fractionation of solutions of glue or gelatin in a four-cell electro-osmotic apparatus, which consists in placing.

the electrodes of such apparatus in bodies of water, interposing between said bodies of water, three diaphragms the central one is permeable to gelatin while the other two are impermeable thereto and in contact with said bodies of water, placing the solution to be-treated, between and in contact with said other two diaphragms, and passing an electric current through the solution in such a manner as to. cause a portion of the gelatin to migrate through the said central diaphragm both anodically and cathodically.

ALEXANDER JENNY. 

